1. Field of the Invention
This invention relates to a manually displaceable implement for ground treatment, comprising a housing, a motor-driven rotor drum rotatably seated in the housing, a connecting piece, and running wheels which are height-adjustable by a spring-loaded height adjustment rod, wherein the running wheels are lowered into a lower end position which is almost free of spring tension and the rotor drum is almost completely lifted off the ground to be treated. This invention is particularly suitable for a ground cutting machine.
2. Description of Prior Art
Implements for ground treatment are employed for cleaning, roughening or cutting of concrete, asphalt or metal surfaces. In general, they have a cage-like, motor-driven rotor drum as a treatment tool, and cage shafts on which several freely rotating beater disks are disposed. The rotor drum is disposed in such a way that the rotating beater disks cut down the surface of the ground to be treated. The setting of the treatment depth is performed by displacing the relative rotor drum shaft in respect to the surface of the ground. Generally this setting is performed by means of height-adjustable running wheels. The forward motion is manually generated by the person operating the implement.
With some embodiments of known implements for ground treatment, the height-adjustable wheels are lowered or raised during non-use. As a result, the rotor drum is either raised and the implement rests on the ground only on its wheels, or the rotor drum is lowered after its drive motor has been turned off and the implement rests only on the rotor drum.
However, in an operational state, all implements for ground treatment have the tendency to run away because of the direction of rotation of the rotor drum. If the operator releases the implement for ground treatment, it makes uncontrollable movements. This is particularly dangerous if the operator releases the implement for ground treatment unexpectedly and involuntarily, for example when feeling sick, when not paying attention or in case of an operating accident.